Model details

Dimensions and weight

• length: 452
• width: 184
• height: 128
• wheelbase: 250
• weight: 1580 kg

Mechanics

• engine displacement: 4957 ccm V8 NA
• drivetrain: RWD
• torque: 430@3000
• power: 320@6000
• weight/power: 4.9
• 0-100: 5.9
• transmission: auto
• tank: 86
• consumption: 14

Production

• production period: 1987–1991
• unit produced: ~15,682 S4

Factory trims and generations

• generations: One 928 generation, 1977–95, extensively evolved 928 → S/S2 → S4 → GT → GTS
• trims: 1991: S4 and sportier manual GT
• exterior colors
  • Standard: Grand Prix White, Black, Maritime Blue, India Red, Signal Green, Mint Green and Rubystone Red
  • Special colours: Polar Silver Metallic, Horizon Blue Metallic, Cobalt Blue Metallic, Oakgreen Metallic, Slate Grey Metallic, Coral Red Metallic, Black Pearl Effect, Midnight Blue Metallic/Pearl Effect, Amethyst Pearl Effect and Amazon Green Pearl Effect
• interior colors:
  • 1991 parts information confirms, among others, Black, Classic Grey, Cobalt Blue, Magenta, Carrara Grey, Sherwood Green and Matador Red leather trim

In/Famous for

Pros

• Probably the car in the collection with the most interesting engineering quirks
• The pop-up headlights do not disappear completely like normal pop-ups—they rotate through approximately 180 degrees and remain visible lying back in the wings
• Because of that design, the headlight lenses can actually be washed while the lights are retracted
• The instrument cluster moves together with the adjustable steering column, so changing steering-wheel height does not hide the gauges
• Has Porsche's Weissach rear axle, effectively a passive rear-steering effect produced through suspension geometry to improve stability
• For 1990–91 it had the electronically controlled PSD locking differential, capable of varying its locking effect
• Had an unusually sophisticated tyre-pressure monitoring system decades before TPMS became commonplace
• Built-in information/diagnostic display was exceptionally advanced for an early-'90s car
• Proper large naturally aspirated 5.0-litre V8 with no turbos or supercharger
• Very good high-speed GT seats; the 928 is famous for being comfortable over genuinely long journeys
• The rear seats fold flat, turning the glass-hatch rear end into a surprisingly useful luggage area
• Much more practical luggage space than a contemporary 911
• Actual rear seats rather than simply a parcel shelf—usable for children or very short adult journeys
• Very unusual combination of a front V8 and rear transaxle, which gives it a fundamentally different character from almost every other Porsche

Cons

• Timing-belt history is critical. A neglected belt can result in very expensive engine damage
• The timing-belt system is enormous and considerably more involved than a simple four-cylinder timing-belt job
• Automatic 928s have a known issue involving crankshaft/thrust-bearing loading associated with the torque-tube/flexplate arrangement; it is something a knowledgeable 928 specialist should check
• Power-steering systems can leak with age
• The huge amount of advanced electrical equipment means there are a lot of 35-year-old electrical systems that can require attention
• Parts can be expensive and you really want somebody who understands 928s specifically rather than simply a general Porsche mechanic. Owner communities repeatedly identify specialist knowledge as important
• Rear seats exist, but legroom is very limited because of the transmission tunnel and packaging
• The 1991 S4 is automatic-only; if you want the 5-speed manual in this model year, you need the 928 GT instead
• Four-speed automatic feels very old compared with the later six/eight-speed gearboxes in the other cars in the collection
• It is a physically big, complicated Porsche, not a lightweight sports car

Special Porsche quirk: the 928 might actually beat the Rapide for the number of genuinely unusual engineering ideas packed into one car.